This invention relates to a terminal assembly for a circuit interrupter, and more particularly to a terminal assembly used with a circuit interrupter to connect a plurality of source terminals and a plurality of load terminals of a circuit interrupter to external electric conductors respectively.
High capacity circuit interrupters generally include a terminal assembly having a structure which is extremely strong and which has good electric insulation because such circuit interrupters generally produce a high electromagnetic force upon the occurrence of a shortcircuit current. A general form of conventional terminal assemblies for a high capacity circuit interrupter has comprised a plurality of source terminals connected to circuits on the source side within the particular circuit interrupter and also to external electric conductors respectively, and a plurality of load terminals connected to circuits on the load side within the circuit interrupter respectively, the arrangement being that those source terminals oppose associated ones of the load terminals, there being one pair of opposite source and load terminals for each of the phases of the circuit interrupter. For example, a terminal assembly for a three phase circuit interrupter includes three pairs of source and load terminals disposed in parallel to one another thereon. Then the plurality of the source and load terminal pairs have electrically insulating side plates therebetween and which are greater in number than the number of the terminal pairs, and a pair of metallic plates are disposed on the outer sides of the outermost side plates respectively. A plurality of bolts extend through the metallic and side plates and are fastened to the metallic plates by means of nuts thereby to fix the source and load terminals to one another.
From the foregoing it is seen that in the conventional terminal assembly, the source terminals, the load terminals and the side plates are collected into separate units each including a plurality of the components and that, after their assembling, the components are connected together into a unitary structure by bolt and nut means.
Thus conventional terminal assemblies such as described above have been disadvantageous in that the assembling operation thereof is extremely difficult, and there is a fear that the source and load terminals may damage the components adjacent thereto due to magnetic forces developed therein, for example because those terminals are permitted only to be fixed to the associated side plates along a relatively short portion thereof.
Accordingly it is an object of the present invention to provide a new and improved terminal assembly for a circuit interrupter capable of being easily assembled and including a plurality of source terminals and a plurality of load terminals which are prevented from shifting due to the magnetic force developed thereon.